Does having a child ruin your life?

Most of my friends have had children and whenever I bring up that I have been getting baby fever and wanting one they all tell me that I will regret having a kid and it will ruin my life. My boyfriend and I have talked a lot about having a baby. I'd prefer to wait a few more years but he thinks he's ready for a child. Do children really ruin your life? Could I be a mother and get and still do things in life? Everyone acts like it's impossible.